Method of purifying solutions of viscose and similar solutions of cellulose



Patented Oct. 7, 1924.

UNITED STATES PATENT OFFICE.

JACOB 1mm NICOLAAS v41! KBEGTEN, 1

NEDEBLARDSCHE ms'rmn NLAILOOZB VENNOOTSCHAI HEM, NETHERLANDS.

KE'IHOD OF PUBIFYIKG SOLUTIONS OF VISCOSE m assumes. no ABBIEK, or m- SOLUTIONS OF OHJLULOSE.

Ho Drawing.

To all whom it may concern:

Be it known that I, J econ Rum NICOLAAB VAN TEN, a subject of the Queen of the Netherlands, residing at Arnhem, Province of Gelderland, Kingdom of the Netherlands, have invented certain new and useful Improvements in or 'Relating to Methods of urifying Solutions of Viscos and Similar Solutions of Cellulose, of which the following is a specification.

It is well known that the purifyin of viscose and similar solutions of cellu ose, which are used for the spinning of artificial silk and other artificial textile products, p sents many difliculties. For obtaining a good spinning solution it is absolutely mu h to purify the raw viscose, obtained by dissolving the cellulose xanthate, bycom letely removing all dirt such as non-attacke fibres of cellulose, or other foreign matter which might obstruct the very fine spinning openings during the spinning operation and thus interfere with the uniformity of the process.

Generally, the cellulose solution is filtered in a filter-pres, the operation being repeated once or more often if re uired. Frequently,

.however, this filtration 1s not suflicient because the very finest particles easily pass through the filter.

e present invention for purifying viscose and similar solutions of cellulose consists in emulsifying intensely the solution with an organic liquid which does not dissolve therein. Th Impurities are now partly dissolved in the organic liquid, partly captured by it. When the emulsion is allowed to settle, the added organic liquid separates slowly from the cellulose solution. Two layers of liquid are thereby obtained; the layer of organic liquid containing the impurities partly in solution and partly in suspension therein, the suspended particles bemg disposed near the boundary between the said layer of organic liquid and the viscose layer, which latter is uitefree from dirt and much less coloured t an before.

A much accelerated separation of the two Application filed November 1:, 1922. Serial Io. 000,686.

liquidsmay be obtained by action of centrlfugal force. The organic liquid then separates very easily and quickly and the purified viscose may be collected easily. By using separators the separation may be made a continual process.

The following advantages of the new process may be cited:

Filter presses are eliminated;

A much purer viscose is obtained than was previously powible;

Substances such as resins (which may originate from the used cellulose) are removed.

The following example illustrates the invention:

100 kilos of viscose are intensely emulsified in a mixing machine with 10 kilos of paraflin oil; the emulsion is then centrifuged.

The separated, purified viscose is spun in the usual manner.

Of course it is possible to use another organic liquid, provided that it does not disolve in the viscose. The method has also the advantage that th organic liquid may be regenerated easily to a very large extent.

What I claim is:

1. A method of purifying viscose and similar solutions of cellulose, comprising emulsifying the cellulose solution with an organic liquid which does not dissolve therein. whereby the impurities contained in said solution will be partly disolved by the 30 organic liquid and will partly remain in suspension in that liquid; and then sepa rating the purified cellulose solution from the organic liquid.

2. A method of purifying viscose and 35 similar solutions of cellulose, comprising emulsifying the cellulose solution with paraflin oil, whereby the impurities contained in said solution will be partly dissolved by the oil but for the most part will remain in suspension in the oil; and then separating the purified cellulose solution from th paraflin oil.

3. A method of purifying viscose and similar solutions of cellulose, comprising the emulsion to the action of oenfli'ifu l emulsifying tho cellulose solution with an force, to so rate the purified cellulose souorganic liquid which does not dimlve theretion from t 0 organic liquid containing the 10 in, whereby the impurities contained in said im urities.

6 solution will be partly dissolved by the orn testimony when-00f I afllx my signature.

ganic liquid and will partldy remain in susension in that liquid; an then subjecting Dr. .IACOI REIII IIICOIAAS m mam. 

